The utility of 18F-FDG and 68Ga-DOTA-Peptide PET/CT in the evaluation of primary pulmonary carcinoid: A systematic review and meta-analysis.

BACKGROUND

Pulmonary carcinoids (PC) are histologically classified into typical carcinoid (TC) and atypical carcinoid (AC). The diagnosis of pulmonary carcinoid and possibly the differentiation between TC and AC could make a significant effect on the treatment planning as well as prognosis. Several studies have explored the utility of Ga-DOTA-Peptide (Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-peptide) and F-flurodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in the evaluation of primary pulmonary carcinoids. Therefore, we performed a meta-analysis to evaluate the diagnostic accuracy and prediction efficiency of histological subtypes of these two imaging modalities in primary PC.

METHODS

Relevant studies were identified by searching PubMed, Web of Science, and EMBASE published from 2006 to 2016. Two authors extracted characteristics of patients and their lesions using predefined criteria.

RESULTS

Fourteen studies comprising 352 patients were included in this meta-analysis. The pooled sensitivity of Ga-DOTA-Peptide and F-FDG PET/CT in detecting pulmonary carcinoid were 90.0% (95% CI = 82.0-95.0%; P = .07; I = 49.6%) and 71.0% (95% CI = 66.0-76.0%; P < .001; I = 59.3%), respectively. An SUVmax ratio between Ga-DOTA-Peptide and F-FDG higher than the cutoff value of 4.28 was predictive of TC with 89.3% sensitivity and 100% specificity (AUC, 96.4%; 95% CI, 91.1-100%). The ratio of tumor uptake to atelectatic lung uptake was significantly higher for Ga-DOTA-peptide (2.5-91, mean 30.5 ± 28.1) than for F-FDG (0.3-10.3, mean 2.1 ± 2.3) (P < .001).

CONCLUSIONS

Both Ga-DOTA-peptide and F-FDG are highly sensitive in detecting pulmonary carcinoid, while Ga-DOTA-peptide is more sensitive than F-FDG (90.0% vs 71.0%). The SUVmax ratio was an accurate predictor of the histopathologic variety of the carcinoid tumor, and Ga-DOTA-peptide was better than F-FDG in cases with atelectasis.